![](../imagenes_titulos/ciencia_kerala02.gif)
by
Godfrey Louis and A. Santhosh Kumar
School of Pure and Applied
Physics, Mahatma Gandhi University,
October 5, 2003
from
arXiv.org Website
Red coloured rain occurred in many places of Kerala in India during
July to September 2001 due to the mixing of huge quantity of
microscopic red cells in the rainwater. Considering its correlation
with a meteor airbust event, this phenomenon raised an extraordinary
question whether the cells are extraterrestrial.
Here we show how the observed features
of the red rain phenomenon can be explained by considering the
fragmentation and atmospheric disintegration of a fragile cometary
body that presumably contains a dense collection of red cells. Slow
settling of cells in the stratosphere explains the continuation of
the phenomenon for two months.
The red cells under study appear to be
the resting spores of an extremophilic microorganism. Possible
presence of these cells in the interstellar clouds is speculated
from its similarity in UV absorption with the 217.5 nm UV extinction
feature of interstellar clouds.
1.
Introduction
Panspermia, the theory that the seeds of life are every where in the
Universe has been gaining more support recently on the basis of
several new findings. Modern version of panspermia considers comets
as the delivery vehicles that spread life throughout a galaxy
1-3.
Comets can protect cells from UV and cosmic radiation damage and
comets can drop cells high in the atmosphere to float gently down
4. Paleogeochemical evidence show that life appeared on Earth as early
as 3,800 million years ago 5 or even before that
6, immediately
following the Earths surface cooling.
This gives too short a time for the
evolution of life to take place from simple precursor molecules to
the level of prokaryotic and photoautotropic cells and it leads to
the argument that life has earlier originated elsewhere and then it
was transported to primitive Earth 7. There is evidence to show that
microbial life can remain in a resting phase for millions of years,
which can enable them to make long space travel
8-11.
There is also the possibility of liquid
water in comets, which could support active life in comets
12-15.
Some of the observational data from comets have also been
interpreted as evidence to prove biological content in comets
16. In
the extreme conditions in comets, if not in active state, life can
be expected to be present as spores. Spores in the dormant state,
undergo no detectable metabolism and exhibit a high degree of
resistance to inactivation by various physical insults
17.
Thus the most possible means by which
microorganisms can arrive in a planet after a journey in space must
be as spores. Considering the universal nature of biochemistry
18,
the chemical makeup of extraterrestrial life forms can be expected
to be similar to the one found on Earth.
Recently there have been a few claims of finding extraterrestrial
life. McKey et al. 19
have found structures similar to microfossils
of nanobacteria in a Martian meteorite, which was interpreted as
evidence for life in Mars. To test the idea of cometary panspermia,
Narliker et al. 20 have performed a stratospheric sample collection
experiment using a balloon and found microorganisms in the air
samples collected over Hyderabad in India at various heights up to
41 km. Wickramasinghe et al. 21, 22, argue that these microorganisms
are of extraterrestrial origin and consider this finding as evidence
to vindicate the idea of cometary panspermia.
In this paper we open a new finding in support of cometary
panspermia. A study of the red rain phenomenon show that the
microscopic cells that coloured the rainwater originated most
possibly from a cometary meteor that disintegrated in the upper
atmosphere above Kerala on 25th July 2001. A physical study of the
cells indicate that the cells are spores of an extremophilic
microorganism and hence we argue that the red rain phenomenon of Kerala is a case of cometary panspermia and the red cells are the
first clear example of life beyond Earth. Though this claim is
extraordinary, there appears no other less extraordinary way to
explain the mystery of red rain in Kerala.
2. The red
rain Phenomenon
The mysterious red rain phenomenon occurred over different parts of
Kerala, a State in India. The news reports of this phenomenon
appeared in Nature 23 and various newspapers and other media and are
currently carried by several websites 24-29. The red coloured rain
first occurred at Changanacherry in Kottayam district on 25th July
2001 and continued to occur with diminishing frequency in Kottayam
and other places in Kerala for about two months.
The red colouring of the rainwater was
found to be entirely due to the presence of tiny red cells about 10
micrometers in size, which appeared dispersed in rainwater. These
cells had some similarity in appearance with alga cells. From the
magnitude of the phenomenon, it can be estimated that several
thousands of kilograms of these cells are required to be there in
the atmosphere to account for all the red rain.
From where the huge quantities of these
cells originate and how they reach the rain clouds to cause red rain
for two months is found to be a mystery. In majority of cases the
colour of the rain was red. There were a few cases of yellow rain
and rare unconfirmed cases of other colours like black, green, grey
etc. Coloured hailstones were another reported case.
It is easy and non-controversial to
dismiss this phenomenon without much study by stating some
conventional, simple and unproved reasons like: dust from Sahara,
pollen grains, volcanic dust from distant volcanoes, fungal spores
from trees, algae from sea and factory pollution etc. But a closer
examination of the features of this phenomenon and the properties of
the cells show that these kinds of reasons are not valid.
A study of the distribution of the red rain incidences with location
and time was done using the data available on this phenomenon. This
data was mostly compiled from the reports that appeared in local
leading Malayalam language newspapers, which have an extensive
network of reporters covering all parts of Kerala. In many cases
photographs of the collected rainwater were given with the news
item.
Being an unusual phenomenon the local
press have given much importance to this. Still there can be several
cases where people have not reported the incidence to the press.
Also there can be several cases, which went unobserved by the
people, such as the cases, which occurred during night. But the
available data is sufficient to show the trend and nature of the
phenomenon (See supplementary information for a list of red rain
incidences with time and place).
A plot (Fig.1a) of the number of coloured rain incidences in Kerala
on different dates shows that about 75% of the total 124 listed
cases occurred during the first 10 days. A plot (Fig.1b) of the
average rainfall data of Kerala enclosing the coloured rain period
from 25th July to 23rd September 2001, demonstrates that the
coloured rain started suddenly during a period of rainfall in the
State.
Thus the cells are not something which
accumulated in the atmosphere during a dry period and washed down on
a first rain. It was found that several cases of red rain phenomenon
have occurred on rainy days after and during normal rains. Thus it
cannot be again assumed that the red cells came from some
accumulation in the lower atmosphere. The vessels kept in open space
also collected red rain.
![](../imagenes_ciencia/cienci1.gif)
Figure 1. Distribution of red rain
a) A plot of the number of coloured
rain incidences in Kerala on different dates. The total number of
cases reported from various parts of the state from 25th July 2001
to the end of September 2001 is 124. These cases are distributed in
time as shown in the figure. 75% of the cases are during the first
10 days.
b) The average of the rainfall recorded in different places in
Kerala from 10th July to 27th September 2001. This record shows that
there was good rainfall before 25th July. The coloured rain
phenomenon started only after the meteor airburst on 25th July 2001.
August 27 to September 16 was a period of no rainfall and hence the
absence of coloured rain reports during that period. The falling red
cells during this no rain period will go unnoticed because of
getting diffused in the wind of the lower atmosphere.
c) The distribution of coloured rain phenomenon in different
districts of Kerala over the full period of its occurrence. The red
rain first occurred at Changanacherry in Kottayam district. The
maximum numbers of cases were reported from Kottayam district on the
subsequent days. Ernakulam and Pathanamthitta, which also show
maximum cases, are adjacent to the north and south of Kottayam
respectively. Alappuzha and Idukki lie on the western and eastern
sides of Kottayam respectively. This distribution is very consistent
with the fall ellipse of a disintegrating meteor, which was moving
from north to south and airbusted over Kottayam district on 25th
July 2001.
Thus it is not something that is washed
out from rooftops or tree leaves. It appears as if the rain clouds
in some region are suddenly mixed with red cells. It may be argued
that the cells arrived here, from a distant source like a desert in
another
part of the world, through some wind system. But in such a system it
is hard to explain the repeated delivery of these cells to target
over a few districts in Kerala for two months while not over other
adjacent States in India, despite the changes in climatic conditions
and wind pattern spanning over two months.
When the red rain reports are viewed in the background of the normal
rainfall data the pattern that emerges is that of a sudden starting
of red rain reports after 25th July 2001 and then a gradual decay of
reports with time. A gap in the red rain reports is due to the
absence of rainfall in the State during that period. If cell clouds
are created in the stratosphere at various heights by a mechanism of
meteor fragmentation and disintegration then clouds of such cells
can slowly settle down to the rain clouds to give such a pattern of
red rain. This idea is elaborated with some actual calculations in
the next section.
The geographical distribution of the red rain cases (Fig.1c.) shows
a clustering of cases in Kottayam and neighbouring districts like
Pathanamthitta, Ernakulam, Idukki and Alappuzha with abrupt decrease
towards the south and gradual decrease towards the north. This
distribution over the geographical area can be explained by
considering the path and the location of final airbust of the
meteor. This idea is also elaborated in the following section.
3. The meteor
connection
Only direct evidence available to support the idea of meteor airbust
is the extreme loud explosive noise heard by people in
Changanacherry in Kottayam district on 25th July early morning where
the red rain was first observed. Even though this matter appeared in
news media we have personally interviewed the people who have
experienced this loud noise to understand the nature of sound they
heard. The people described the sound they heard at about 5:30 a.m.
on 25th July 2001, as an extremely loud and sharp noise which was
distinctly different from thunder.
Their description of the nature of the
sound agrees with that of a sonic boom from a meteor
30-32. Sonic
boom is a high amplitude low frequency sound, which lasts for only a
fraction of a second. This kind of infrasonic sound can induce
resonant vibrations in building structures giving the fearsome
impression of a roof collapse which some of them agreed to have
experienced.
The sound cannot be that of a thunder
because thunderstorms are characterized by a series of small and
large lightning strokes and in the present case people heard only
one loud bang. Thus it can be reasonably argued that the extreme
loud noise heard by the people was a sonic boom and a meteor
airburst did take place on 25th morning. The red rain was first
observed at Changanacherry a few hours later at around 8:45 a.m. on
the same day. Then on the following days there were reports of red
rain from other places which are separated by as distant as few
hundred kilometers.
The first indirect evidence for a meteor connection emerges when one
looks at the distribution of red rain incidences over the
geographical area. If the final stages of meteor fall was over
Kottayam and near by districts then these places should receive
maximum amount of red rain. This is found to be true from the red
rain’s geographic distribution pattern as shown in (Fig.1c).
The path of the meteor travel can also
be guessed from the geographical distribution pattern. Usually
during a large meteor fall, fragmentation of the original body takes
place and these fragments appear to be distributed over an
elliptical area 33, 34. This region (Fig. 2) in the present case has
a size of 450 km by 150 km. This large area is possibly due to the
fragile nature of this cometary meteor, which causes fragmentation
during its flight in the upper atmosphere at a low angle.
The fragments would get disintegrated to
fine particles during its downward travel. Thus each of the
fragments can form a column of fine particles made up of red cells.
Each of these columns, which make slow vertical decent from the
stratosphere, can finally interact with the rain clouds to cause
highly localized red rain phenomenon at different places.
![](../imagenes_ciencia/cienci2.gif)
Figure 2. Fall ellipse of the
cometary meteor
The direction of meteor travel and the
fall ellipse, as inferred from the pattern of red rain occurrence in
various places. The meteor had probably airbusted above an area
between Changanacherry and Pathanamthitta while moving in the
southeast direction shown by the dashed line. The fragments of the
fragile meteor got disintegrated and turned into packets of
particles in the atmosphere, which subsequently caused red rain and
associated phenomenon by mixing with rain clouds. The fall ellipse
has a size of about 450 km by 150 km and the red rain phenomenon
occurred within this elliptical region. There are no reports of red
rain from the neighbouring states Tamil Nadu and Karnataka. The
distance per degree of latitude and longitude in Kerala region is
about 110 km/deg.
Hence each case of red rain report can be equated to a fragment of
the meteor. Maximum cases of red rain and associated phenomenon
occurred at places in Pathanamthitta and Kottayam and Ernakulam
districts (Fig. 1c far above), starting from the first few days of red rain
phenomenon. These districts mark the head of the elliptical region.
The tail region lies in the Kannur district in the north. From the
above pattern of red rain, it can be inferred that while falling to
the ground like a reentering space craft the meteor has travelled
from north to south in a south-east direction above Kerala as shown
in Figure 2 and airbusted above Kottayam district.
Since the airbust occurred above Kottayam, only very little
fragments reached the south most district Thiruvananthapuram causing
little red rain there.
The second indirect evidence is the distribution of the occurrences
of red rain in time. This distribution of the red rain in time can
be explained using a calculation of the settling rate of the cells
in the stratosphere. The dominant mechanism by which particles are
removed from stratosphere is by particle settling.
The settling
velocity of small spherical particles is described mathematically by
Stokes Law, given as:
![](../imagenes_ciencia/cienci3.gif)
![](../imagenes_ciencia/cienci4.gif)
The red rain particles are of about 10
micrometers in size and assuming their density as one and half times
as that of water, the settling velocity of these particles are
computed using Eq. 1 and tabulated in Table 1 for various altitudes
in the atmosphere.
![](../imagenes_ciencia/cienci5.gif)
Table 1. Settling
velocity of cells in atmosphere
The table lists the computed settling
velocity (using Eq.1), at various altitudes in Earth’s atmosphere,
for spherical particles having a size of 10 micrometers and density
1500 Kg/m3. This table shows that the settling velocity do not vary
widely with altitude, despite the large variation in air density.
The values of air density and viscosity are that of international
standard atmosphere.
From this, for the stratosphere, the average settling velocity for a
red rain cell can be approximated as 0.5 km per day. This shows
that, in the absence of any turbulence, such a cell can take 60 days
to travel down 30 km in the stratosphere. Thus it is theoretically
possible for the red rain phenomenon to occur over the same
geographical region for extended periods like 60 days if the
stratosphere above that region contains suspended red rain particles
at different heights. Disintegrating fragile cometary meteor, which
contain huge quantities loosely packed red rain cells can deposit
the same in the stratosphere at different heights.
Depending upon the height into which the
collection of particles were thrown into the atmosphere during the
disintegration of meteor fragments in the air, the time they take to
reach the rain clouds can differ. This explains the temporal
distribution of red rain. Above simple modelling only gives an
approximate solution to the actual situation. Presence of air
movement or wind, variations in particle size (size has square
dependence), shape and density, clustering and adhesion of small
particles to form large grains etc. can greatly increase or decrease
the settling rate.
Thus micro particles in the stratosphere
can remain there for several months before finally reaching the
ground. In the absence of rain clouds, the settling red rain causing
particles will be invisible if they reach lower atmosphere, as they
will get dispersed in the wind. Thus if the meteor disintegration
occurred during a dry season this phenomenon would have gone
unnoticed.
Above analysis explain why the red rain phenomenon can last for long
period like two months or more. It explains why the red rain
suddenly appeared almost simultaneously at different places in
Kerala, which are separated 200 to 300 km. It explains the origin of
huge quantity of cells amounting to several thousand kilograms with
the assumption that a cometary body which carry such cells exists.
It explains why the phenomenon did not occur in
neighboring states
Karnataka and Tamil Nadu while it made repeated appearance for two
months, mostly concentrated in certain districts in Kerala. But it
appears impossible to find a natural terrestrial process, which can
account for these features of the red rain and provide such
explanations.
4. The red
rain cells
The samples of red rain cells required for the study were obtained
from widely different geographical locations separated by more than
100 kilometers from districts of Kottayam, Pathanamthitta and
Ernakulam. The characteristics of the cells collected from different
places were the same showing a common origin. The red rain cells
appears in the rainwater as a fine suspension.
![](../imagenes_ciencia/cienci6.jpg)
Figure 3. Red rainwater and cells
a) Images of the Red
Rainwater collected by some people in Pathanamthitta in their
stainless steel household vessels. These images show the
characteristic reddish brown colour of the red rain. An approximate
calculation shows that at least 50 tones of cells are required to
account for the total reported red rain cases in Kerala. This
requires a cometary object of at least 10 meters in size with a very
dense collection of red cells in it.
b) Photomicrograph of the red rain microorganisms under 400x
magnification. Note the transparent nature of the cells. Cells at
the bottom can be seen through the one on the top. Bar indicates 10
�m.
c) Photomicrograph of the red rain microorganisms under 1000x
magnification. The cells show variations in shape and size. The
cells show a layered structure and a cell envelope. Size varies from
4 to 12 micrometers. Bar indicates 10 �m.
This gives the water a reddish brown colour (Fig. 3a). The cells are
about 10 micrometers in size, almost transparent red in colour and
are well dispersed in the rainwater. The resulting colour of the
rainwater is not turbid, but it has an appearance like a red dye
solution.
Colour of the diluted red wine and red colour with a tint
of pink under reflected light are matching descriptions for the red
rainwater. When allowed to stand for several hours the cells settle
to the bottom of the vessel and the water becomes colourless.
![](../imagenes_ciencia/cienci7.jpg)
Figure 4. Dyed cell and heated
cells
a) Photomicrograph (1000x) of a
single red rain cell which was stained by using acidified methyl
green dye. Staining was achieved by keeping the cells in dye
solution for few hours. For most of the cells, the dye did not
penetrate beyond the first outer layer. For some cells as the one
shown in figure, the dye reached the central core and produced a
blue coloration there. Bar indicates 5 �m.
b) Photomicrograph (1000x) of the red cells which underwent
heating to a temperature of 370) C. Water was added after heating to
aid photomicrography. The size of the cells got reduced by about 20%
as a result of heating. Their colour turned dark brown and the cell
walls has become more visible. The black rain, which occurred at a
few places, is possibly due to the presence of burnt cells, which
resulted from the heating during airburst and fireball phase of the
meteor. Bar indicates 10 �m.
Under low magnification cells look like smooth, coloured glass beads
(Fig. 3b). Under high magnifications (1000 x) their differences in
size and shape can be seen (Fig. 3c). Shapes vary from spherical to
ellipsoidal and slightly elongated types. The thick and coloured
cell envelope of the cells can be well identified under the
microscope. In a large collection only a few were found to have a
broken cell envelope. No nucleus could be observed in the cells even
after staining with acidified methyl green dye (Fig. 4a).
The cell after the dye the penetration
clearly shows a layered structure. The majority of the red rain
cells have reddish brown colour but a small percentage of cells are
white or have colours with light yellow, bluish grey and green
tints. To further ascertain the biological nature of these cells,
they were tested for cell proteins by Xanthoproteic test. In which
the cells were heated with concentrated HNO3 and then treated with NaOH solution. The yellow coloration of the solution indicated the
presence of proteins in the cells.
The cells were subjected to some
physical and chemical conditions to test their ability to survive
extreme conditions. The cell wall is not damaged by H2SO4 but was
found to get digested by concentrated HNO3. The cells retained its colour and shape even after boiling in water for several minutes. To
test how the cells would change on dry heating, it was placed in a
heating stage under microscopic observation.
As the temperature was increased
progressively to a maximum of 370) C, the colour of the cells
changed more and more brownish and finally blacker. No rupture or
breaking of the cell wall took place, but a certain amount of
shrinking in the size of the cells could be noticed (Fig. 4b). The
cell wall could be seen clearly even after the heat treatment.
However, the colour change and size reduction started occurring only
on heating above 200) C, which suggests that these cells are
possibly having an ability to survive heating while entering a
planetary atmosphere.
To study the effect of low pressure, the
cells were placed in a vacuum chamber and the pressure was reduced
to 0.01 millibar. No damage could be seen for the cells after this
low-pressure treatment. This shows that the cells can survive low
pressure without damage.
![](../imagenes_ciencia/cienci8.gif)
Figure 5. UV visible absorbance
spectrum of red rainwater
This is the spectrum of a
dilute suspension of red cells in water. A notable feature is the
significant absorption in the UV region, indicating the presence of
UV screening compounds in the cell, which could be a mechanism
adopted by the microorganisms to escape from the damaging UV
radiation in space.
The red rain was subjected to a spectrophotometric examination. The
UV- Visible absorption spectrum of the cells suspended in water is
shown in Fig. 5. The spectrum was recorded in comparison with
distilled water using a Shimadzu model UV-2401 PC spectrophotometer.
The spectrum shows significant absorption of UV radiation by the
cells.
This can be interpreted as an indication
of the presence of effective UV screening compounds in the cells.
Thus the cells can possibly survive the damaging UV radiation in
space. The peak UV absorption occurs near 200 nm and this has
important significance in explaining the interstellar UV extinction
curve, as discussed in next section.
5. Discussion
on cosmic origin of cells
Interstellar dust is now recognized as an important component of the
interstellar medium and it is considered to play an important role
in the evolution of galaxies, the formation of stars and planetary
systems, and possibly, the origins of life
35. Findings during the
past few decades show that a wide range of organic compounds exist
in the interstellar clouds contrary to the earlier idea that
interstellar dust clouds are inorganic grains.
As an extrapolation to these findings,
it is now more conceivable than the past to think of the possibility
of actual microorganisms in interstellar clouds and their possible
arrival to Earth through comets. One of the reasons for assuming the
presence of microorganisms in the interstellar clouds is the UV
absorption characteristic of the interstellar clouds in which a peak
is found near 217.5 nm 36. Several explanations have been proposed
by many to explain this interstellar extinction curve
37. But none
of these explanations are fully successful to explain the curve
38.
Hoyle et al. 39-42 have shown that the UV extinction curve is
explainable by assuming the presence of microorganisms as a
component of interstellar cloud and supported this claim using their
experiments and theoretical considerations. Findings by some other
researchers also do not rule out the possibility of microorganisms
in interstellar clouds 43-45.
In this context the presence of red rain
cells in interstellar space as a component of the dust clouds can be
speculated on the basis of the UV absorption property of the red
rain cells. The cells suspended in water shows a strong peak near
200 nm (Fig. 5). If this peak is shifted to 217.5 nm then it can
account for the interstellar UV extinction. It is to be seen whether
the red rain cells, when existing in interstellar space like
conditions of low temperature and high vacuum, will show a shift in
absorption peak to 217.5 nm. If so then the presence of red rain
cells in interstellar clouds can be suspected.
Comets, which originated in the
interstellar clouds as aggregates of red cells and dust grains,
embedded in an icy matrix of gaseous compounds can be captured by
the Sun during its passage through an interstellar cloud
46. Such
comets can later seed the planets or the cells and dust that
survived the formation of the solar system can also end up in comets
to seed the planets. Thus cells in the interstellar clouds can reach
planets as expected in cometary panspermia.
Panspermia also requires the opposite process of transport of cells
from planets to interstellar clouds. In radiopanspermia single
exposed microorganisms are accelerated to high velocity by stellar
radiation pressure and leave a solar system and finally reach
interstellar space 47. In the present context we find that red rain
cells have high UV shielding property to escape the damaging UV
radiation from a star.
They have larger size (3 to 4 times)
when compared to bacterial spores, which means more radiation
pressure on them to move away from the star. If the mass of the
cells remain low due low density under dehydration, then radiation
pressure can dominate over gravitational attraction. When the Sun
like stars reach red-giant stage, the temperature in Earth like
planets increase to high levels where only extremophilic organisms
can survive.
Finally when the oceans in the planets
evaporate away it can possibly launch the spores of extremophilic
organisms like the red rain cells into space along with the water vapour. During a red-giant phase a star emit less UV radiation, thus
cause low harm to microbes in space. The cells driven out from the
planet eventually reach the interstellar space and act as potential
seeds to seed later planetary systems in a next generation star.
Thus life can possibly continue to exist through several generations
of stars.
In this paper we have shown how the red
biological cells that caused the red rain phenomenon of Kerala may
have originated from a cometary body. As further supporting work we
have investigated the growth conditions and the reproduction
techniques of the red rain extremophiles. We will be reporting
immediately the extraordinary results of this study in another
paper.
Acknowledgements
G. L. is the main author and is
responsible for the facts and claims presented in this paper. A. S.
K. has contributed to the paper by giving valuable assistance to G.
L. for this investigation. We greatly acknowledge the help of George Varughese for collecting many of the samples and important
information about the phenomenon.
We thank Dr. A. M. Thomas for first
approaching us with a coloured rainwater sample and Dr. Sabu Thomas
for providing photomicrography facility. We also thank the teaching,
administrative and technical staff members, research scholars and
students of SPAP and several others who have encouraged and helped
this work.
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Supplementary
Information
A List of 124 reports of colored rain
cases in Kerala during the period July –September 2001, compiled
from various news reports and other sources (List sorted by
district).
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